CAPSChain Assembly and Packing Suite

Learn by doing

Tutorials

Each tutorial is a complete route through one kind of project, with commands that were run as written. Runs are kept short so they finish on a laptop; the text says where a production study needs longer ones.

01Your first amorphous polymer cellGrow polystyrene chains in a periodic box, relax them, run molecular dynamics, and measure density, chain size and stiffness, using five commands.5 minutes · grow · relax · md · analyze · check · render02Force fields and engine inputsType a structure with OPLS-AA or PCFF, inspect the assignment, and write complete inputs for LAMMPS and GROMACS.5 minutes · ff info · ff type · ff apply03Recipes, provenance and a methods paragraphDescribe a whole study in one YAML file, run it with one command, and get the methods paragraph, BibTeX and a record that shows exactly how two runs differ.5 minutes · run · provenance04Crosslinking a rubber networkCure natural rubber with a peroxide template inside CAPS, or export the same chemistry as a LAMMPS fix bond/react set with typed templates.10 minutes · Python · react · bond_react · export_engines05Coarse-graining a polyesterMap an all-atom poly(butylene succinate) run onto beads, invert bonded and non-bonded potentials, build a long-chain melt, measure entanglements, and put the atoms back.15 minutes · cgmap · cgfit · cgbuild · ppa · cgdyn · mech · backmap06A DFT surface studyCut a Ti₃C₂ MXene sheet, terminate it with O, OH and F, validate it, place a nitrile on it, and write VASP case folders ready for a Slurm cluster.10 minutes · sheet · terminate · validate · adsorb-dft · vasp-set · vasp-jobs · vasp-analyze07Analysing trajectoriesDensity, structure, chain dimensions, dynamics, free volume and cohesive energy from any trajectory CAPS reads, with errors, curves for plotting, and figures.10 minutes · analyze · rdf · chains · frames · render · pipeline